Trying to build critical mass for small communities

Hi, I'm focusing on generating content for a few communities that I feel can be successful and have less content than I expected:

• !cassettefuturism@lemm.ee: a genre of retrofuturism based on the 70's and 80's (more info)
• !awwnverts@lemmy.world: cute invertebrates
• !weirdwheels@lemmy.world: weird vehicles (with wheels)
• !comicstrips@lemmy.world: self-explanatory

EDIT: I did not create any of those communities

I would encourage anyone to participate if you like those topics.

Do you know any other niche-but-not-too-niche communities in which we could focus efforts?
Please, don't post very long lists, I'm already subscribed to almost 300 communities and the idea is to focus on a few ones.

Thanks!

EDIT: Added descriptions for each community.